Capital Additions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	$ 3,373	$ 3,117	$ 3,705
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	3,163	2,182	3,433
Operating Segments | Thin-film Equipment Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	700	1,433	2,230
Operating Segments | Photonics
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	2,463	749	1,203
Unallocated Amount to Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	$ 210	$ 935	$ 272